Tracking 2.3-16 Valve - PeachParts Mercedes-Benz Forum

Motodisiac · #1 10-27-2006, 02:25 AM

Well, I just got my "new" 16 valve and plan to track it as soon as possible. I'm looking for people's opinions on different wheels / tires. Originally I wanted to get some 17" wheels with 235/40/17 (the size I ran in my E30 M3) but it looks like I better stick with 16's for better performance. How about 225/50/16? Looking for your advice for tracking this car, anything I should expect? I will be installing H&R cup kit next weekend. How does the car compare to usual track day cars (BMW's, MINI's etc) Does it oversteer or understeer (sway bars needed?) What tire pressure I should start with? I would be very happy to hear your track experiences. Thanks!

Dennis

mbdoc · #2 10-31-2006, 08:21 AM

How serious are you?

IF you just want to run autocross & want to go fast there then a set of Hoosier 225X45X15's are as good as you can get!

The front anti-sway bar needs to be 25MM for that application.

Motodisiac · #3 11-01-2006, 01:57 AM

Doc!

Thanks for replying. I'm not planning to RACE it. I don't like autocross because it's too short and doesn't give you the feeling you get on open track. I WILL do track days and some time trials at least once a month, and maybe drive it couple times a month (I commute on a bike so the car is a back up only) I want to have two sets of wheels, one for the street and one for the track. I noticed that you raced 16V in SCCA. Hopefully you can share your setup findings a little bit, it's always very costly to learn by trial and error. The tire size you mentioned is not available in any competition tires. I'm thinking about using lightweight 16" wheels for the track (225/50/16, about 1 inch taller than stock tire) My other option would be to run stock 15's on the track with 225/50/15 tire (a bit smaller diameter than stock, and less expensve too!) Please share your knowledge!
Now to the swaybars. I haven't pushed the car yet, so I'm not sure if it will oversteer or understeer. Most production cars are set up to understeer, which is solved my thicker REAR bar. You recommend thicker FRONT. Does it mean the car OVERSTEERS in stock form? Unfortunately there is not a lot of choice when it comes to buying one, it will be a challenge. I know someone who can custom make one for me, but I need to provide the specs.
How about alignment specs? What's the best way to set it up? I like my car to turn in fast and be neutral with a tiny bit of understeer correctable with some throttle.
Well, looking forward to hear back from you. Any information will be valuable to me, I cannod find a single person who has any knowlege on this car going beyond installng big rims and loud stereos. Thanks!

mbdoc · #4 11-01-2006, 08:59 AM

For track days use the Hoosier 225X45XZR15's. Raced with them for years...they are the "fastest" of the DOT street race tires. Tire Rack has those tires in stock for track(R version) OR for autocross (A version)....The Kumho's are almost as fast.

I tried several front sway bars but settled on a E500 bar that I modified to fit.

yhliem · #5 11-01-2006, 12:00 PM

By no means at all do I have Doc's level of experience, but here are my own personal observations and preferences for setting up my 16v. Take it into consideration or discard it completely; it's up to you.

My 16v is setup as follows:

Springs: Eibach Pro-Kit lowering springs
Shocks/Struts: OEM (Yes, SLS is intact)
Front Swaybar: W124 Sportline 27.5mm 124-323-68-65 (modified to fit)
(For reference, 500E Front Swaybar is p/n 124-323-72-65)
Rear Swaybar: EvoII 18mm 201-326-37-65
Rear Swaybar links: 300TE 124-320-04-89
#1 Spring Pads (8mm) Fr: 201-321-09-84 Rr: 201-325-11-44
Rims: 7Jx16H2 7-hole CLK Lightweight
Tires: Falken Azenis 512 215/45-16

I was running in the equivalent to SCCA ST/S class this past summer and wound up 3rd (out of over 20) in class and 10th (out of approx 130) overall in my club's Novice Championship series. The two cars ahead of me in my class were a 2001 Subaru Impreza 2.5RS and a 2003 Acurar RSX. My 16v is also the oldest car in the top 20.

Observations:

I had the front swaybar installed a couple of years ago. At the time I noticed a significant reduction in preceived body-roll (seat of the pants instrumentation). At the same time, however, there was a definite increase in understeer when pushing the car.

For the first part of the season I ran the car with the springs, front swaybar and the 300TE rear swaybar links (these are metal as opposed to the stock plastic ones) and the car would understeer at the limit. Once I put the EvoII rear swaybar in the car rotates a LOT more easily and tends to power-on oversteer. it was noticable even driving on the street. During autocross the car handles like a considerably smaller car. Unfortunately the mass is all still there so the limits aren't the same as most other cars.

I received several comments from more experienced autocrossers about this. They said that just watching my runs the car looked like it rotates very easily. I've had a few senior drivers drive my car a few times at they were nothing short of amazed at how well sorted the suspension was. The car, for it's size and mass, handles very, very well.

Now, for the caveat. In the wet, the car is definitely more tailhappy, so more judicious use of the throttle is required when coming out of the corners.

As for the rims and tires, my choice is limited by my brakes. I have EvoII/500E 4-pot Brembos in the front and cannot fit 15" rims on the car. So I HAVE to use 16". This presents a bit of a problem since the 2.3-16 uses an odd OEM tire size (205/55-15). Plus 1 fitment is 225/45-16 instead of the more popular 225/50-16. 225/50-16s will not fit on my car because it's lowered and there will be significant rubbing at the front of the front wheelarch where the bumper and fender sheetmetal meet. I suspect that on a full-height 16v it may be possible to fit this size.

NoSpark · #6 11-01-2006, 03:49 PM

If you're gonna do some casual track time, do yourself a favor and not dump money into your car. Stick with the stock rims and tire sizes, and leave well enough alone. The problems with the racing community, including even the hobbyist, is that you wind up throwing money at theoretical go-fast goodies or try to keep up with the big spenders.

There will always be the guy who spends $30k on some headwork and benchflow testing (i personally know a guy who spent $40k on a 4cyl Cosworth head), and several thousand dollars on rims to save a 1/2 pound of unsprung weight. The hobbyist leaves the sport broke trying to keep up with the front runners. I've seen guys with $2500 tow rigs who think it's perfectly reasonable to spend $25,000 on a new racing motor.

Best to spend your time and money on making you safe. Just preparing the car for a race weekend will eat up your every weeknight. If you must spend money, I recommend a proper racing seat w/ a 5-point harness along with a roll cage.

Edit: Most every 16v I've come across the last few years sagged in the rear...the self-levelling system had seen better years. That would cause a nasty push.

Motodisiac · #7 11-03-2006, 12:18 AM

Arent 225/45/15's smaller than stock by nearly an inch?
E500 bas sounds like something I should look into.

D.

Quote:

Originally Posted by M.B.DOC

For track days use the Hoosier 225X45XZR15's. Raced with them for years...they are the "fastest" of the DOT street race tires. Tire Rack has those tires in stock for track(R version) OR for autocross (A version)....The Kumho's are almost as fast.

I tried several front sway bars but settled on a E500 bar that I modified to fit.

Motodisiac · #8 11-03-2006, 12:31 AM

That's what I'm talking about! Thanks for sharing your setup. I've been looking into these 16" forged wheels myself, there are few sets for sale on Flea Bay. How much do they weigh? I've heard different opinions, from 13 to 18 lbs. Yesterday I installed H&R cup kit, took the spring pads out complitely (I wish I read this post before!) Now the car is way too low, will order #1 pads tomorrow (car came with #2's) You privided me with some very valuable information, thank you again. What alignment specs are you running? Since I'm going to get my brakes upgraded (I have to) I might want to try to make 225/50/16's fit, there are so many tire choices. It's only 1 inch taller than stock size, about 12mm of tire on each side. I'l make it wirk, I know exactly where it will rub, I've seen few 16V's with holes from rubbing there! My main objectve is to make the car handle well with minimal investment.

D.

Quote:

Originally Posted by yhliem

By no means at all do I have Doc's level of experience, but here are my own personal observations and preferences for setting up my 16v. Take it into consideration or discard it completely; it's up to you.

My 16v is setup as follows:

Springs: Eibach Pro-Kit lowering springs
Shocks/Struts: OEM (Yes, SLS is intact)
Front Swaybar: W124 Sportline 27.5mm 124-323-68-65 (modified to fit)
(For reference, 500E Front Swaybar is p/n 124-323-72-65)
Rear Swaybar: EvoII 18mm 201-326-37-65
Rear Swaybar links: 300TE 124-320-04-89
#1 Spring Pads (8mm) Fr: 201-321-09-84 Rr: 201-325-11-44
Rims: 7Jx16H2 7-hole CLK Lightweight
Tires: Falken Azenis 512 215/45-16

I was running in the equivalent to SCCA ST/S class this past summer and wound up 3rd (out of over 20) in class and 10th (out of approx 130) overall in my club's Novice Championship series. The two cars ahead of me in my class were a 2001 Subaru Impreza 2.5RS and a 2003 Acurar RSX. My 16v is also the oldest car in the top 20.

Observations:

I had the front swaybar installed a couple of years ago. At the time I noticed a significant reduction in preceived body-roll (seat of the pants instrumentation). At the same time, however, there was a definite increase in understeer when pushing the car.

For the first part of the season I ran the car with the springs, front swaybar and the 300TE rear swaybar links (these are metal as opposed to the stock plastic ones) and the car would understeer at the limit. Once I put the EvoII rear swaybar in the car rotates a LOT more easily and tends to power-on oversteer. it was noticable even driving on the street. During autocross the car handles like a considerably smaller car. Unfortunately the mass is all still there so the limits aren't the same as most other cars.

I received several comments from more experienced autocrossers about this. They said that just watching my runs the car looked like it rotates very easily. I've had a few senior drivers drive my car a few times at they were nothing short of amazed at how well sorted the suspension was. The car, for it's size and mass, handles very, very well.

Now, for the caveat. In the wet, the car is definitely more tailhappy, so more judicious use of the throttle is required when coming out of the corners.

As for the rims and tires, my choice is limited by my brakes. I have EvoII/500E 4-pot Brembos in the front and cannot fit 15" rims on the car. So I HAVE to use 16". This presents a bit of a problem since the 2.3-16 uses an odd OEM tire size (205/55-15). Plus 1 fitment is 225/45-16 instead of the more popular 225/50-16. 225/50-16s will not fit on my car because it's lowered and there will be significant rubbing at the front of the front wheelarch where the bumper and fender sheetmetal meet. I suspect that on a full-height 16v it may be possible to fit this size.

Motodisiac · #9 11-03-2006, 12:45 AM

I'm with you on this subject. I'm not planning to throw a ton of $$ into go fast goodies, I just want to make it a little more trackable. I've been on the track in a car with stock suspension and it's no fun at all and even scary. I just want to make it fun! I'm past the stage where one buys cold air intakes and hi performance wires.

D.

Quote:

Originally Posted by NoSpark

If you're gonna do some casual track time, do yourself a favor and not dump money into your car. Stick with the stock rims and tire sizes, and leave well enough alone. The problems with the racing community, including even the hobbyist, is that you wind up throwing money at theoretical go-fast goodies or try to keep up with the big spenders.

There will always be the guy who spends $30k on some headwork and benchflow testing (i personally know a guy who spent $40k on a 4cyl Cosworth head), and several thousand dollars on rims to save a 1/2 pound of unsprung weight. The hobbyist leaves the sport broke trying to keep up with the front runners. I've seen guys with $2500 tow rigs who think it's perfectly reasonable to spend $25,000 on a new racing motor.

Best to spend your time and money on making you safe. Just preparing the car for a race weekend will eat up your every weeknight. If you must spend money, I recommend a proper racing seat w/ a 5-point harness along with a roll cage.

Edit: Most every 16v I've come across the last few years sagged in the rear...the self-levelling system had seen better years. That would cause a nasty push.

NoSpark · #10 11-03-2006, 11:54 AM

It's all about hooking up. Some pics of my brother. Had the race won then the motor hand grenaded. Big time.

yhliem · #11 11-03-2006, 12:08 PM

Quote:

Originally Posted by Motodisiac

That's what I'm talking about! Thanks for sharing your setup. I've been looking into these 16" forged wheels myself, there are few sets for sale on Flea Bay. How much do they weigh? I've heard different opinions, from 13 to 18 lbs. Yesterday I installed H&R cup kit, took the spring pads out complitely (I wish I read this post before!) Now the car is way too low, will order #1 pads tomorrow (car came with #2's) You privided me with some very valuable information, thank you again. What alignment specs are you running? Since I'm going to get my brakes upgraded (I have to) I might want to try to make 225/50/16's fit, there are so many tire choices. It's only 1 inch taller than stock size, about 12mm of tire on each side. I'l make it wirk, I know exactly where it will rub, I've seen few 16V's with holes from rubbing there! My main objectve is to make the car handle well with minimal investment.

D.

No problem.

I don't know the actual weight of the rims but 13-18 lbs sounds about right.
I'm running stock alignment specs (or as close as I can since the rear has quite a bit of neg camber due to lowering).

If you *do* go with 225/50-16s don't forget to allow space for tire deflection. A tire that clears the bodywork by a few mm's when cycling the suspension & turning the wheels on a lift may not clear when the car is actually running on the street/track and the suspension (and tire) is under dynamic loading.

Another little bit of advice: replace all the suspension bushings front and rear, but especially the rear. There are 5 suspension links per side and 2 bushings per link. That's 20 rubber bushings that allow some deflection in the suspension. If the bushings are worn that adds up to a LOT of play.

I typically advise against solid links (ie heim joints) on MBs unless the car is a dedicated race car only. The rear suspension has been engineered with bushings of specific hardness to allow for some deflection as the suspension cycles. If you delete the bushings and substitute solid joints any deflection that was engineered into the system is gone. As a result the mounting points of the suspension links have to deal with more loading than they were intitially intended to.

Furthermore dedicated race cars (depending on the discipline and driver preference of course) tend to run very stiff suspensions with not much travel so the requirement for non-rigid joints is minimal to begin with. (Watch some old DTM vids, or if you've seen the pics of Klaus Ludwig's #3 Sonax car up on the air jacks you'll see what I mean)